Dover resident, Bob Kovack, shovels off a layer of ice-covered snow from the walkway of his home. Robert Sciarrino/The Star-Ledger

The wintry mix swirling over New Jersey has led to a messy, slippery and slow commute this morning.

"Numerous" minor accidents along Interstates 287, 80 and 78, the Garden State Parkway and New Jersey Turnpike have bogged down traffic since about 4 a.m., Sgt. Adam Grossman of the New Jersey State Police said.

According to 511nj.org, specific delays due to crashes are scattered over the main commuting corridors:

• A jack-knifed tractor-trailer on Interstate 78 East in Springfield closed lanes for several hours and delayed traffic by as much as 10 minutes. The accident has apparently been cleared by 9 a.m., the website shows.

• Accidents on the New Jersey Turnpike in Newark, Kearny and Secaucus created a mess along the entire northbound stretch of the highway for several hours this morning, as well.

The precipitation is expected to continue through the morning commute and into the workday, but will turn mostly to rain as temperatures increase, according to Lee Robertson, a meteorologist with the National Weather Service's Mount Holly office. A winter weather advisory is in effect for much of the area: Morris, Sussex, Warren, Hunterdon, Somerset, Passaic, Bergen and the western parts of Essex and Union counties, Robertson said. The advisories extend to 11 a.m., except for Sussex - which lasts until 3 p.m., Robertson said.

All the rain and snow should end by sunset, Robertson added.

The NWS has called for as much as 6 inches of snow in New Jersey's higher elevations before the precipitation changes to freezing rain. The highest snowfall total so far was recorded in Lafayette Township, at 4.8 inches.

However, the evening commute could be complicated by dropping temperatures - and increasingly slippery roads - in some of the northern parts of the state, Robertson added.

Many schools in northwest Jersey have a delayed opening because of the slippery roads caused by today's winter weather.

The state police is urging everyone on the roads to take their time traveling this morning.